Update neon_matrix_impl.c

Issue 1507: can't compile kazmath lib on arm64
CCLabelTTF documentation
CCLabelBMFont comment tweak
Bug #368
See issue notes for benchmarks
Merge pull request #385 from cocojoe/develop-v3

CCLabelTTF documentation
Merge pull request #355 from frranck/patch-1

Update neon_matrix_impl.c